(Bloomberg) — Prime Minister David Cameron made an impassioned plea to the British people to consider their children’s futures before voting on whether the U.K. should stay in the European Union.

In a direct address to voters from outside his Downing Street residence in central London Tuesday, Cameron asked the country to put aside its personal views of him and heed the multiple voices arguing that EU membership made Britain stronger, safer and richer. “Of this, every living prime minister, whether Labour or Conservative, is convinced,” he said.

“I want to speak very directly to those of my generation and older,” Cameron said. “Do think about the hopes and dreams of your children and grandchildren. They can’t undo the decision we take. If we vote out, that’s it. It is irreversible. We will leave Europe for good. And the next generation will have to live with the consequences.”

The intervention, delivered without prior notice, suggests the prime minister may be less convinced than investors that momentum is firmly with his “Remain” campaign less than two days before Thursday’s referendum. Moments before Cameron spoke, the pound pared gains as a poll by Survation showed “Remain” on 45 percent and “Leave” on 44 percent, a one-point lead that is within the margin of error.

Click here for a guide on what to look out for on the night of the vote count

Royal biographer Robert Lacey reported that Queen Elizabeth II has recently been asking dinner companions for “three good reasons why Britain should be part of Europe.” Lacey, writing in a blog on the Daily Beast website, said that the queen’s sympathies may “on occasions, like those of many of her subjects, have veered towards Brexit.”

Asked about the report, Buckingham Palace said in an e-mailed statement: “The Queen is above politics and acts on the advice of Her Government in political matters. The referendum is a matter for the British people to decide.”

While latest opinion polls still signal a tight vote, bookmakers and currency markets suggest that “Remain” is in a strong position heading into the final 36 hours of campaigning. The pound held near the strongest level against the dollar since January, while an index of odds compiled by the Oddschecker survey put the probability of a vote to leave at 25 percent, down from 45 percent a week earlier.

‘Pandora’s Box’

Soros, who made $1 billion betting on a devaluation of the pound in 1992, warned in the Guardian newspaper that leaving the EU could cut the value of sterling by as much as 20 percent.

“That is a huge risk to Britain, to British families, to British jobs,” Cameron said. “Brits don’t quit. We get involved. We take a lead. We make a difference. We get things done.”

Pro-Brexit Justice Secretary Michael Gove ridiculed the billionaire investor’s comments. “If economic forecasters were as reliable as doctors or airline pilots, then everyone would be a billionaire,” Gove told BBC Radio. “The truth is that economic forecasters like George Soros have got things wrong in the past.”

The Brexit referendum is being monitored by governments, politicians and investors around the world amid concern a vote to leave the EU could encourage anti-establishment sentiment elsewhere and heighten global instability. Spain’s Acting Economy Minister Luis de Guindos, campaigning ahead of his country’s general election on Sunday, said the vote has opened “a Pandora’s box of populism.”

Yellen, Draghi, Beckham

The final big set-piece before the referendum is scheduled for Tuesday evening, when former London Mayor Boris Johnson and his pro-EU successor, Sadiq Khan, take part in a BBC Television debate at London’s Wembley Arena.

Political leaders and central bankers issued fresh warnings. In Washington, Federal Reserve Chair Janet Yellen said a Brexit could roil currency markets and hurt the U.S. economy while Mario Draghi said the European Central Bank might act to contain the fallout. The ECB is prepared to stabilize markets, provide liquidity and deploy existing swap lines with other central banks, Draghi told a European Parliament hearing in Brussels.

As Cameron spoke, his former adviser Steve Hilton was touring TV studios arguing that the prime minister had been told in 2012 he couldn’t reduce immigration while Britain was inside the EU. Cameron addressed this indirectly, saying his job was to keep the country safe. “I would not be standing here, encouraging you to vote to remain in the EU if I thought that the EU stopped me from doing that,” he said.

For many voters, the biggest intervention of the day may have come over breakfast, when David Beckham, the former England soccer team captain, became the latest celebrity to support “Remain.” “For our children and their children we should be facing the problems of the world together and not alone,” Beckham tweeted.